The present invention relates to a cannula for receiving surgical instruments for performing a surgical procedure on a body.
A known cannula for receiving surgical instruments is disclosed in U.S. Pat. No. 6,187,000. U.S. Pat. No. 6,187,000 discloses a cannula having an expandable portion. The expandable portion has a slot and a guide member disposed in the slot. The guide member is movable from a first terminal end of the slot to a second terminal end of the slot to enable the cross-sectional area of a passage in the cannula to increase.
The present invention is a cannula for receiving surgical instruments for performing a surgical procedure on a body. The cannula includes a tube structure defining a passage through which the surgical instruments are inserted into the body. The tube structure includes an expandable portion for enabling an increase in the cross-sectional area of the passage.
The expandable portion of the tube structure has a slot and a guide member disposed in the slot. The guide member is movable from a first end of the slot toward a second end of the slot to enable the cross-sectional area of the passage to increase. The expandable portion has a stop between the first and second ends of the slot engageable with the guide member. The stop retains the guide member in a position relative to the slot and resists movement of the guide member relative to the slot from the position.